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Thread: Why do es everone put a bushing in bolt face of pps43

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    Gunco Member rapidrus's Avatar
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    Default Why do es everone put a bushing in bolt face of pps43

    Title says it all I was wondering why? Im putting floating firing pin in bolt, to me the bushing looks unneeded why wouldnt the original diameter work? but this is my first 43, and if I was sure I would not be asking you

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    No Hope For Me Coils's Avatar
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    ....................................
    Last edited by Coils; 06-07-2011 at 01:29 AM.
    "Government is not the solution to our problem, government is the problem" Ronald Reagan

  3. #3
    Gunco Member rapidrus's Avatar
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    that fairly large hole is just shy of 3/16, the problem with using original firing pin as bushing is it is to small to plug hole. I was hoping some one would chime in and say that a 3/16 firing pin would work?!<

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    Gunco Good ole boy kernelkrink's Avatar
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    3/16" = .1875. Small pistol primer diameter = .175. With a 3/16" FP the primer will back out of the case when fired, jamming it up.

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    Gunco Member rapidrus's Avatar
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    I guess Im real bad at describng what I want to try. The 3/16 pin would be tapered like any other firing pin. I may just try it and give a report,

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    Gunco Good ole boy kernelkrink's Avatar
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    You're not getting the picture. I understand you are using a large shaft FP with a point on it. That is not an issue.

    The hole in the bolt is larger than the primer. The primer, unless it is supported by the boltface, will want to blow itself out of the case. The spring tension on the FP is not enough to prevent this. The bushing lets the small diameter FP hit the primer, and the bushing supports the primer in the case.

  7. #7
    Gunco Member rapidrus's Avatar
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    Quote Originally Posted by kernelkrink View Post
    You're not getting the picture. I understand you are using a large shaft FP with a point on it. That is not an issue.

    The hole in the bolt is larger than the primer. The primer, unless it is supported by the boltface, will want to blow itself out of the case. The spring tension on the FP is not enough to prevent this. The bushing lets the small diameter FP hit the primer, and the bushing supports the primer in the case.
    I think I do understand, Im not trying to come off as smart ass just wanting to learn, The hole size is the same as original firing pin. Why did it work?

  8. #8
    Gunco Good ole boy kernelkrink's Avatar
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    The original firing pin is fixed, it doesn't retract. The PPS43, like most SMGs, is open bolt. The firing pin sticks out all the time, and the larger diameter portion of it sits even with the boltface, providing the needed support. When the bolt slams shut, the round comes to a stop in the chamber and the fixed FP continues forward with the last fraction of bolt travel to set off the primer. In a closed bolt semi, the FP must retract below the bolt face to prevent slamfires. If you don't bush the hole, that will leave a hole larger than the primer with a cone shaped FP sticking up in the middle. Depending on how far below flush the FP tip is, the primer will either blow back into the hole unimpeded or only partially extrude down around the cone. Either way, jam city and possible gas leakage. Even with a round using the larger diameter large pistol primers, enough is unsupported that extrusion back into the hole is likely.

    Think of it this way, that small little protrusion on the original FP is the FP, the larger diameter part is simply what holds it in the bolt and is indistinguishable from the bolt when installed, from a function standpoint.

  9. #9
    Gunco Member rapidrus's Avatar
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    OK I got it . thanks for taking time to draw me a picture. I will bush it,

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    Gunco Veteran Bolt2bounce's Avatar
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    That was a good job of explaining it kernel, I shot my pps43C this weekend. The gun ran flawless, but the Ammo had some hard primes so I had a few that needed a second trip under the Pin.. only about 2% B2B

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